Domperidone versus metoclopramide in the treatment of diabetic gastroparesis

Research progress on the roles of dopamine and dopamine receptors in digestive system diseases

Dopamine (DA) is a neurotransmitter synthesized in the human body that acts on multiple organs throughout the body, reaching them through the blood circulation. Neurotransmitters are special molecules that act as messengers by binding to receptors at chemical synapses between neurons. As ligands, they mainly bind to corresponding receptors on central or peripheral tissue cells. Signalling through chemical synapses is involved in regulating the activities of various body systems. Lack of DA or a decrease in DA levels in the brain can lead to serious diseases such as Parkinson's disease, schizophrenia, addiction and attention deficit disorder. It is widely recognized that DA is closely related to neurological diseases. As research on the roles of brain-gut peptides in human physiology and pathology has deepened in recent years, the regulatory role of neurotransmitters in digestive system diseases has gradually attracted researchers' attention, and research on DA has expanded to the field of digestive system diseases. This review mainly elaborates on the research progress on the roles of DA and DRs related to digestive system diseases. Starting from the biochemical and pharmacological properties of DA and DRs, it discusses the therapeutic value of DA- and DR-related drugs for digestive system diseases.

Current Treatment Options and Therapeutic Insights for Gastrointestinal Dysmotility and Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGIDs) have been re-named as disorders of gut-brain interactions. These conditions are not only common in clinical practice, but also in the community. In reference to the Rome IV criteria, the most common FGIDs, include functional dyspepsia (FD) and irritable bowel syndrome (IBS). Additionally, there is substantial overlap of these disorders and other specific gastrointestinal motility disorders, such as gastroparesis. These disorders are heterogeneous and are intertwined with several proposed pathophysiological mechanisms, such as altered gut motility, intestinal barrier dysfunction, gut immune dysfunction, visceral hypersensitivity, altered GI secretion, presence and degree of bile acid malabsorption, microbial dysbiosis, and alterations to the gut-brain axis. The treatment options currently available include lifestyle modifications, dietary and gut microbiota manipulation interventions including fecal microbiota transplantation, prokinetics, antispasmodics, laxatives, and centrally and peripherally acting neuromodulators. However, treatment that targets the pathophysiological mechanisms underlying the symptoms are scanty. Pharmacological agents that are developed based on the cellular and molecular mechanisms underlying pathologies of these disorders might provide the best avenue for future pharmaceutical development. The currently available therapies lack long-term effectiveness and safety for their use to treat motility disorders and FGIDs. Furthermore, the fundamental challenges in treating these disorders should be defined; for instance, 1. Cause and effect cannot be disentangled between symptoms and pathophysiological mechanisms due to current therapies that entail the off-label use of medications to treat symptoms. 2. Despite the knowledge that the microbiota in our gut plays an essential part in maintaining gut health, their exact functions in gut homeostasis are still unclear. What constitutes a healthy microbiome and further, the precise definition of gut microbial dysbiosis is lacking. More comprehensive, large-scale, and longitudinal studies utilizing multi-omics data are needed to dissect the exact contribution of gut microbial alterations in disease pathogenesis. Accordingly, we review the current treatment options, clinical insight on pathophysiology, therapeutic modalities, current challenges, and therapeutic clues for the clinical care and management of functional dyspepsia, gastroparesis, irritable bowel syndrome, functional constipation, and functional diarrhea.

Efficacy of Pro-Kinetic Agents in Type 2 Diabetes Mellitus Patients With Gastroparesis Using Lactulose Hydrogen Breath Testing: A Randomized Trial

Aim

The aim of the study was to determine the efficacy of prokinetic agents in diabetic gastroparesis patients.

Method

This was a randomized open-label trial conducted on 50 patients with type 2 diabetes experiencing diabetic gastroparesis, which was diagnosed with the lactulose hydrogen breath test. After randomization, all 50 patients were divided into four arms (cinitapride, metoclopramide, levosulpiride, and domperidone) of different prokinetics and followed up for four weeks; after which, repeat gastroparesis cardinal symptom index score and orocecal transit time were recorded in order to assess the response to the treatment.

Result

There was no statistically significant difference among the four groups in terms of all the baseline characteristics except for gender (p=0.032). The follow-up gastroparesis cardinal symptom index was collected for 50 patients but repeat orocecal transit time could be performed only in 37 patients. In all four groups, there was a statistically significant (p<0.05) improvement in terms of orocecal transit time and gastroparesis cardinal symptom index scores. But there was no statistically significant difference in relative efficacy amongst these study groups.

Conclusion

Our study showed statistically significant improvement with four prokinetics drugs in terms of gastroparesis cardinal symptom index score and orocecal transit time, but there was no statistically significant benefit of one prokinetic drug over the other. Our study showed promising results with regard to prokinetic use in diabetic gastroparesis.

Association between Domperidone Administered via Feeding Tube and Feeding Success in Critically Ill Patients with Enteral Feeding Intolerance

One nutritional challenge in critically ill patients is enteral feeding intolerance (EFI), but current prokinetic agents have uncertain efficacy and safety profiles. We conducted a longitudinal, single-center, retrospective study to evaluate the efficacy and safety of domperidone administered via the feeding tube versus intravenous (IV) metoclopramide among adult patients with EFI. The primary outcome was feeding success, defined as the proportion of patients with average percentage of daily protein prescription >80% of the target dose. The secondary outcomes were safety endpoints. Among 28,814 intensive care unit (ICU) admissions, 552 patients with EFI were included, 38 receiving IV metoclopramide and 514 receiving tube feeding domperidone. The proportion of feeding success in patients receiving tube feeding domperidone and IV metoclopramide was 42.02% and 21.05%, respectively. After 1:2 matching (IV metoclopramide to tube feeding domperidone), the proportion of feeding success was 40.79% in patients receiving tube feeding domperidone. Basically, after matching, there were no differences in any safety endpoints (mortality and length of stay during ICU and hospitalization, organ-support-treatment free days) or adverse events (recurrence of EFI, electrolyte disturbance, abdominal and other symptoms) between the two groups (p > 0.05). A logistic regression analysis in the matched cohort indicated that domperidone administered via the feeding tube was independently associated with feeding success. We found that tube feeding domperidone was efficient in increasing enteral nutrition delivery performance among critically ill adult patients with EFI.

Pancreas transplantation would be easy if the recipients were not diabetic: A practical guide to post-operative management of diabetic complications in pancreas transplant recipients

Diabetes mellitus remains a major public health problem throughout the United States with over $300 billion spent in total cost of care annually. In addition to being a leading cost of kidney failure, diabetes causes a host of secondary hyperglycemic-related complications including gastroparesis and orthostatic hypotension. While pancreas transplantation has been established as an effective treatment for diabetes, providing long-term normoglycemia in recipients, the secondary complications of diabetes mellitus persist complicating the post-operative course of an otherwise successful pancreas transplantation. This review describes the mechanism and impact of diabetic gastroparesis and orthostatic hypotension in the post-operative course of pancreas transplant patients and analyzes the various treatment modalities, based on current data and extensive experience at our institution, to treat these respective complications. While gastroparesis and orthostatic hypotension remain challenging post-operative conditions, the establishment of institutional protocols and step-up treatment algorithms can help define more effective therapies.

Risk of domperidone induced severe ventricular arrhythmia

There has been controversy over the cardiovascular safety of domperidone, attributable to the lack of a well-designed study as well as inconsistent results. This study aimed to examine the risk of severe domperidone-induced ventricular arrhythmia (VA), compared to mosapride, itopride, or non-use of all three prokinetics, in the general population. We conducted a population-based, self-controlled case series analysis. Enrolled subjects were individuals who were diagnosed with severe VA and were prescribed domperidone, mosapride, or itopride from 2003 to 2013 in the National Health Insurance Service-National Sample Cohort. The incidence rate ratio for severe VA was measured during exposure to prokinetics and compared with unexposed periods and itopride (no-proarrhythmic effect)-exposure periods, as control. A total of 2,817 subjects were included. Domperidone, mosapride, or itopride use was associated with increased risk of severe VA, compared with non-use (adjusted incidence rate ratios (IRR) of 1.342 (95% CI 1.096–1.642), 1.350 (95% CI 1.105–1.650), and 1.486 (95% CI 1.196–1.845), respectively). The risk of severe domperidone-induced VA was lower, compared to that of itopride [adjusted IRR of 0.548 (95% CI 0.345–0.870)]. Of the subjects who had been prescribed all three prokinetics, domperidone-exposure was associated with a lower risk of severe VA, compared to itopride-exposure (crude IRR, 0.571; 0.358–0.912). Mosapride-exposure did not show IRR difference for severe VA, compared to itopride-exposure. Domperidone, mosapride, or itopride use is associated with an increased risk of severe VA. However, the magnitude of association was modest and domperidone use does not increase further the risk, compared with other prokinetics.

Gastric electrical stimulation: An emerging therapy for children with intractable gastroparesis

Management of gastroparesis remains challenging, particularly in pediatric patients. Supportive care and pharmacological therapies for symptoms remain the mainstay treatment. Although they are effective for mild and some moderately severe cases, often time they do not work for severe gastroparesis. There are a few prokinetics available, yet the use of these drugs is limited by a lack of persistent efficacy and/or safety concerns. Currently, the only modality for adult patients with severe intractable gastroparesis is surgery, e.g., pyloroplasty and partial gastrectomy, however, this option is generally considered too radical for a growing child. Novel therapeutic approaches, particularly those which are less invasive, are needed. This article explores gastric electrical stimulation (GES), a new therapy for gastroparesis. Unlike others, it neither needs medications nor gastrectomy; rather, it treats through the use of microelectrodes to deliver high-frequency low energy electric stimulation to the pacemaker area of the stomach. Thus, it is tolerated and safe in children. Like in adult patients, GES appears to work in releasing symptoms, improving nutrition, and enhancing the quality of life; it also helps wean off medications and eliminate many needs for hospitalization. Considering the transient nature of gastroparesis in children in many occasions, GES is considered a “bridging” therapy after failed medical interventions and before surgery.

Pharmacological Approaches to Diabetic Gastroparesis: A systematic review of randomised clinical trials

Pharmacological interventions of diabetic gastroparesis (DG) constitute an essential element of a patient’s management. This article aimed to systematically review the available pharmacological approaches of DG, including their efficacy and safety. A total of 24 randomised clinical trials (RCTs) that investigated the efficacy and/or safety of medications targeting DG symptoms were identified using several online databases. Their results revealed that metoclopramide was the only approved drug for accelerating gastric emptying and improving disease symptoms. However, this medication may have several adverse effects on the cardiovascular and nervous systems, which might be resolved with a new intranasal preparation. Acceptable alternatives are oral domperidone for patients without cardiovascular risk factors or intravenous erythromycin for hospitalised patients. Preliminary data indicated that relamorelin and prucalopride are novel candidates that have proven to be effective and safe. Future RCTs should be conducted based on unified guidelines using universal diagnostic modalities to reveal reliable and comprehensive outcomes.

A Meta-Analysis of the Efficacy of Prokinetic Agents against Glycemic Control

Background

Prokinetic agents are used in diabetic gastroparesis patients to improve gastric emptying and upper gastrointestinal (GI) symptoms. However, the efficacy of prokinetic agents against glycemic control is questionable. Therefore, we conducted a systemic review and meta-analysis to determine the efficacy of prokinetic agents against glycemic control.

Methods

Randomized controlled trials (RCTs) evaluating the effect of prokinetics were identified by searching PubMed, Embase, and the Cochrane Library databases until April 2018. The primary outcome was changes in the mean value of glycosylated hemoglobin (HbA1c), fasting blood sugar (FBS), and fasting serum insulin (FINS). The pooled standardized mean differences (SMD) with 95% confidence intervals (CIs) were calculated by evaluating the strength of the association. We used the random effect models to analyze these markers. The effects of each component of the prokinetic agents on glycemic control were separately analyzed.

Results

Five RCTs with 190 patients met the criteria and were included in the meta-analysis. There were statistically significant SMD between prokinetics and placebo-controlled groups with respect to the reduction of HbA1c (-1.141, 95% CI -1.843, -0.438; P < 0.01). No statistically significant differences were noted between the two groups for FBS (-1.270, 95% CI -2.613, -0.074; P = 0.06) and FINS (0.359, 95% CI -1.205~1.923; P = 0.65).

Conclusions

Prokinetics have a positive effect on glycemic control. Further large-scale prospective studies are needed.

Symptomatic Management of Gastroparesis

Gastroparesis is a chronic and debilitating neuromuscular disorder of the upper gastrointestinal tract. Symptoms of gastroparesis include nausea, vomiting, epigastric pain, early satiety, and weight loss. Treating gastroparesis can be difficult. Dietary changes may improve symptoms in patients with mild disease. A variety of medications can be used to treat symptoms of nausea and vomiting, although most have not been subjected to randomized controlled trials and only one is approved by the Food and Drug Administration (metoclopramide). Pain management is essential, as nearly 90% of patients report symptoms of epigastric pain. This article reviews treatment options for symptoms of gastroparesis.

State of the art review with literature summary on gastric peroral endoscopic pyloromyotomy for gastroparesis

Gastroparesis is a debilitating progressive disease that significantly impacts a patient's life with limited and challenging treatments available. Although the pathogenesis is multifactorial, pylorospasm is believed to have a major underlying role. Several therapeutic interventions directed to the pylorus have been developed over the last decade, including intra-pyloric injections of botulinum toxin, transpyloric stenting, and surgical pyloroplasty. All of these treatment options had limited and disappointing results. More recently, gastric peroral endoscopic myotomy (G-POEM) has been reported as a treatment for refractory gastroparesis. In this review article, we provide an overview on gastroparesis with a focus on the therapeutic interventions. In addition, we provide a literature summary and pool analysis of the clinical efficacy, scintigraphic efficacy, and safety profile of all studies that evaluated G-POEM in gastroparesis. Overall, seven studies have reported on the use of G-POEM in gastroparesis, and the pooled analysis of these studies showed a technical success of 100%, with clinical efficacy as assessed by the Gastroparesis Cardinal Symptoms Index of 81.5%, gastric emptying scintigraphy normalization in approximately 55.5% of the cases, perioperative complications in 7.6%, and intraoperative complications in 6.6%. This suggests that G-POEM is a new promising therapeutic intervention for the treatment of gastroparesis with durable effect and limited potential adverse events.

Gastroparesis: Medical and Therapeutic Advances

Gastroparesis is a chronic, bothersome, and often disabling neuromuscular disorder of the upper gastrointestinal tract. The most frequently reported symptoms of gastroparesis include nausea, vomiting, epigastric pain, early satiety, and unintentional weight loss. Etiologies of gastroparesis include diabetes, connective tissue disorders, prior infection, mesenteric ischemia, and post-surgical complications. The largest category of gastroparesis patients is comprised of those in whom no definitive cause can be identified (idiopathic gastroparesis). The individual and societal burden of gastroparesis is substantial. It considerably reduces patients' quality of life accompanied by a significant negative impact to the healthcare system. The current treatments of gastroparesis are less than ideal. Dietary modification may improve symptoms in patients with mild disease. Metoclopramide is the only medication currently approved for the treatment of gastroparesis; however, it is associated with adverse effects in a sizable proportion of patients. Other medications are frequently employed to treat symptoms of nausea and vomiting, although technically all are used off-label since they are not FDA approved for the treatment of gastroparesis. These data highlight the need to identify novel, more effective treatment options for this disabling disease. This review will provide a brief synopsis on the epidemiology, etiology, and impact of gastroparesis, discussing new therapeutic advances.

G-POEM with antro-pyloromyotomy for the treatment of refractory gastroparesis: mid-term follow-up and factors predicting outcome

BACKGROUND

Gastric peroral endoscopic pyloromyotomy (G-POEM) was introduced for treating refractory gastroparesis.

AIM

To present a series of patients focussed on clinical mid-term efficacy and predictive outcomes factors.

METHODS

This was a single centre study of 29 patients operated on between January 2014 and April 2016, with disturbed gastric emptying scintigraphy (GES) and/or elevated Gastroparesis Cardinal Symptoms Index (GCSI). The procedures were performed as previously described. The primary endpoint was the efficacy at 3 and 6 months, based on GCSI and symptoms. The secondary endpoints were GES evolution, procedure reproducibility and safety, and identification of predictive factors for success.

RESULTS

There were 10 men, 19 women (mean age 52.8±18). The technical success rate was 100% (average 47 minutes). There were two complications managed conservatively: one bleeding and one abscess. The median follow-up was 10±6.4 months. The clinical success rate was 79% at 3 months, 69% at 6 months, with a significant decrease in the mean GCSI compared to pre-operatively (3.3±0.9 vs 1±1.2 and 1.1±0.9 respectively). The GES (n=23) normalised in 70% of cases, with a significant improvement of the mean half emptying time and retention at 2 hours, and a discordance in 21% of the cases. In univariate analysis, diabetes and female gender were significantly associated with risk of failure, but not confirmed in multivariate analysis.

CONCLUSIONS

The mid-term efficacy of G-POEM reaches 70% at 6 months. The procedure remains reproducible and safe. Diabetes and female gender were predictive of failure.

Gastric per-oral endoscopic myotomy with antropyloromyotomy in the treatment of refractory gastroparesis: clinical experience with follow-up and scintigraphic evaluation (with video)

BACKGROUND AND AIMS

Gastroparesis is a chronic, debilitating condition. We report an experience conducting gastric per-oral endoscopic pyloromyotomy (G-POEM) with objectives to assess clinical efficacy, gastric emptying evolution, and procedural adverse events.

METHODS

This was a clinical pilot series on 12 consecutive patients who underwent G-POEM for refractory gastroparesis in our tertiary center between February 2014 and August 2015. Patients included had severe disease as defined by elevated Gastroparesis Cardinal Symptoms Index (GCSI) score and delayed gastric emptying scintigraphy (GES). G-POEM was performed by mucosal incision upstream the pylorus followed by submucosal tunnel and antropyloromyotomy with subsequent access closure. Efficacy was assessed at 5 days, 1 month, and 3 months, based on GCSI score, and individualizing (Likert scale) the main symptoms (nausea, vomiting, abdominal pain, early satiety, and anorexia). GES was performed 2 months after the procedure.

RESULTS

G-POEM was successfully performed in all 12 patients, yielding a technical success rate of 100%. Significant improvements in GCSI were observed: 3.5 ± .8 versus .9 ± .9 (1 month) and 1.1 ± 1.5 (3 months), respectively (P < .001), as well as the severity of main symptoms at 3 months. Clinical efficacy was 85% (10/12). GES normalized in 75% of cases, with improvement of half emptying time (222 ± 90 minutes vs 133 ± 90 minutes; P = .03) and retention at 2 hours (76% ± 20% vs 44% ± 26%; P = .009). There were no adverse events related to the procedure.

CONCLUSION

We report a single-center study evaluating G-POEM for refractory gastroparesis, demonstrating its feasibility, reproducibility, and safety with promising clinical and scintigraphic efficacy.

Domperidone and Risk of Ventricular Arrhythmia and Cardiac Death: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Domperidone is a drug used globally for relieving nausea and vomiting and stimulating breast milk production. Several case reports and studies linked domperidone usage with major cardiovascular adverse events (cardiac arrhythmia and sudden cardiac death). However, multiple randomized controlled efficacy studies failed to detect such adverse events. Our objectives were to systematically review and meta-analyze the association between current domperidone exposure and cardiovascular adverse events.

METHODS

The first author performed EMBASE, PubMed and Scopus searches to identify human studies assessing the association between current domperidone exposure and cardiac arrhythmia or sudden death. Thirteen related articles were identified and the first and second authors independently reviewed the articles. Six studies were included in the final analysis. Meta-analysis was performed with a random effect model using the inverse variance approach. Heterogeneity was evaluated using the Q statistic and I(2) test.

RESULTS

Five case-control studies and one case-crossover study were included in this meta-analysis. Pooled risk estimates demonstrated that the current use of domperidone increased the risk of ventricular arrhythmia and sudden cardiac death (pooled adjusted odds ratio = 1.70; 95% confidence interval 1.47-1.97; I(2) = 0%). The I(2) test showed that the underlying population was homogeneous.

CONCLUSIONS

Evidence from this meta-analysis suggests that current domperidone use increases the risk of cardiac arrhythmia and sudden cardiac death by 70%. Domperidone usage in older populations should be discouraged. Larger observational studies or randomized controlled trials are needed to confirm the findings of this analysis.

Pathophysiology and pharmacotherapy of gastroparesis: current and future perspectives

INTRODUCTION

Gastroparesis is an important clinical disorder characterised by delayed gastric emptying in the absence of mechanical outlet obstruction. Idiopathic, diabetes and postsurgical causes represent the most common aetiologies. The condition commonly manifests as upper gastrointestinal symptoms, including nausea, vomiting, postprandial fullness, early satiety, abdominal pain and bloating.

AREAS COVERED

This paper provides a review of the prevalence, pathophysiology and clinical features associated with gastroparesis, with a particular focus on current pharmacological management options and novel and emerging therapies. A literature search was undertaken using the search terms: gastroparesis, diabetic gastroparesis, idiopathic gastroparesis, gastric emptying, prokinetic, metoclopramide, domperidone, erythromycin, motilin, alemcinal, KC11458, mitemcinal, ghrelin, TZP-101, TZP-102, RM-131, tegaserod, prucalopride, naronapride, velusetrag, levosulpiride, itopride, botulinum toxin, gastric electrical stimulation, Enterra.

EXPERT OPINION

Strategies for the management of gastroparesis include correction of malnutrition, dehydration and electrolyte imbalance, relief of symptoms by appropriate use of prokinetic and antiemetic agents and, in patients with gastroparesis associated with diabetes or critical illness-induced hyperglycaemia, optimisation of glycaemic control. Conventional prokinetic agents form the mainstay of treatment. While novel pharmacotherapies are in development, compelling evidence for their efficacy, particularly in symptom relief, remains to be established.

Recent advances in the pathophysiology and treatment of gastroparesis

Gastroparesis is a clinical disorder characterized by upper gastrointestinal symptoms related with delayed gastric emptying of solids and liquids in the absence of mechanical obstruction. Diabetes mellitus has been the most common cause of gastroparesis and idiopathic gastroparesis also accounts for a third of all chronic cases. The most important mechanisms of gastroparesis, as understood to date, are loss of expression of neuronal nitric oxide synthase and loss of the interstitial cells of Cajal. However, the pathogenesis of gastroparesis is poorly understood. There have been several studies on specific molecules related to the pathogenesis of gastroparesis. Additionally, the Gastroparesis Clinical Research Consortium of the National Institutes of Health has achieved several promising results regarding the pathophysiology of gastroparesis. As the progress in the pathophysiology of gastroparesis has been made, a promising new drug therapy has been found. The pathophysiology and drug therapy of gastroparesis are focused in this review. Until now, the real-world medication options for treatment of gastroparesis are limited. However, it is expected to be substantially improved as the pathophysiology of gastroparesis is elucidated.

[Gastroparesis: pathophysiology and management]

The prevalence of gastroparesis is increasing. Diabetes mellitus and sequelae of œsogastric surgery are the two main causes of gastroparesis. In some patients, gastroparesis seems a postinfectious disease after its sudden onset after a viral infection. In about one third of the patients, gastroparesis is considered as idiopathic. In diabetic patients, gastroparesis impairs glycaemic control. Due to the low positive predictive value of symptoms, a gastric emptying study is often necessary to confirm a suspected diagnosis of gastroparesis. The symptomatic efficacy of erythromycin is higher than that of other prokinetics. This efficacy is higher when erythromycin is given intravenously. Hyperglycaemia impairs this symptomatic effect. Due to a tachyphylaxis phenomenon, the clinical effect of erythromycin decreases with the duration of treatment. In refractory gastroperis, either duodenal or jejunal enteral feeding, or high-frequency gastric electrical stimulation are possible therapeutic options while endoscopic alternatives (intrapyloric botulinum injection or pyloric balloon dilation) give unsatisfactory results.

Domperidone treatment for gastroparesis: demographic and pharmacogenetic characterization of clinical efficacy and side-effects

BACKGROUND

Domperidone is a useful alternative to metoclopramide for treatment of gastroparesis due to better tolerability. Effectiveness and side-effects from domperidone may be influenced by patient-related factors including polymorphisms in genes encoding drug-metabolizing enzymes, drug transporters, and domperidone targets.

AIMS

The aim of this study was to determine if demographic and pharmacogenetic parameters of patients receiving domperidone are associated with response to treatment or side-effects.

METHODS

Patients treated with domperidone for gastroparesis provided saliva samples from which DNA was extracted. Fourteen single-nucleotide polymorphisms (SNPs) in seven candidate genes (ABCB1, CYP2D6, DRD2, KCNE1, KCNE2, KCNH2, KCNQ1) were used for genotyping. SNP microarrays were used to assess single-nucleotide polymorphisms in the ADRA1A, ADRA1B, and ADRA1D loci.

RESULTS

Forty-eight patients treated with domperidone participated in the study. DNA was successfully obtained from each patient. Age was associated with effectiveness of domperidone (p=0.0088). Genetic polymorphism in KCNH2 was associated with effectiveness of domperidone (p=0.041). The efficacious dose was associated with polymorphism in ABCB1 gene (p=0.0277). The side-effects of domperidone were significantly associated with the SNPs in the promoter region of ADRA1D gene.

CONCLUSIONS

Genetic characteristics associated with response to domperidone therapy included polymorphisms in the drug transporter gene ABCB1, the potassium channel KCNH2 gene, and α1D--adrenoceptor ADRA1D gene. Age was associated with a beneficial response to domperidone. If verified in a larger population, this information might be used to help determine which patients with gastroparesis might respond to domperidone and avoid treatment in those who might develop side-effects.

Diabetic gastroparesis: Therapeutic options

Gastroparesis is a condition characterized by delayed gastric emptying and the most common known underlying cause is diabetes mellitus. Symptoms include nausea, vomiting, abdominal fullness, and early satiety, which impact to varying degrees on the patient's quality of life. Symptoms and deficits do not necessarily relate to each other, hence despite significant abnormalities in gastric emptying, some individuals have only minimal symptoms and, conversely, severe symptoms do not always relate to measures of gastric emptying. Prokinetic agents such as metoclopramide, domperidone, and erythromycin enhance gastric motility and have remained the mainstay of treatment for several decades, despite unwanted side effects and numerous drug interactions. Mechanical therapies such as endoscopic pyloric botulinum toxin injection, gastric electrical stimulation, and gastrostomy or jejunostomy are used in intractable diabetic gastroparesis (DG), refractory to prokinetic therapies. Mitemcinal and TZP-101 are novel investigational motilin receptor and ghrelin agonists, respectively, and show promise in the treatment of DG. The aim of this review is to provide an update on prokinetic and mechanical therapies in the treatment of DG.

Gastroparesis: current concepts and management

Delayed gastric emptying in the absence of mechanical obstruction is referred to as gastroparesis. Symptoms that are often attributed to gastroparesis include postprandial fullness, nausea, and vomiting. Although tests of gastric motor function may aid diagnostic labeling, their contribution to determining the treatment approach is often limited. Although clinical suspicion of gastroparesis warrants the exclusion of mechanical causes and serum electrolyte imbalances, followed by empirical treatment with a gastroprokinetic such as domperidone or metoclopramide, evidence that these drugs are effective for patients with gastroparesis is far from overwhelming. In refractory cases with severe weight loss, invasive therapeutics such as inserting a feeding jejunostomy tube, intrapyloric injection of botulinum toxin, surgical (partial) gastrectomy, and implantable gastric electrical stimulation are occasionally considered.

Review article: The diagnosis and management of gastroparesis

BACKGROUND

Gastroparesis is a disorder characterized by a delay in gastric emptying of a meal in the absence of a mechanical gastric outlet obstruction.

AIM

To provide an evidence based overview on diagnosis and management of gastroparesis.

METHODS

A PubMed search was performed using search terms including gastroparesis, gastric retention, gastric emptying, accommodation, manometry, prokinetics, antiemetics, metoclopramide, domperidone, erythromycin, botulinum toxin, gastric pacing. Relevant studies were identified and original articles and reviews were collected. References in these articles were examined for relevance and included where appropriate.

RESULTS

Diagnosis of gastroparesis is based on the presence of symptoms such as nausea, vomiting and postprandial abdominal fullness and on an objectively determined delay in gastric emptying. The true prevalence of gastroparesis is unknown. Gastric emptying can be assessed by scintigraphy and stable isotope breath tests. Management of gastroparesis consists of dietary and lifestyle measures and/or pharmacological interventions (prokinetics, antiemetics, intrapyloric botulinum toxin injection) or other interventions that focus on adequate nutrient intake either through a nasoduodenal tube, percutaneous gastrostomy or jejunostomy.

CONCLUSIONS

Accurate diagnosis of gastroparesis requires an adequate protocol to measure gastric emptying. Treatment options in gastroparesis remain limited despite the disabling nature of the disorder.

The difficult patient with gastroparesis

Gastroparesis is often difficult to manage. First of all, exact criteria for making a diagnosis of gastroparesis have not been established, and merely finding delayed gastric emptying does not justify the label. Furthermore, the relationship between symptoms and gastric emptying rate is poor, and the number of therapies with proven efficacy is extremely limited. A number of technical investigations are helpful to establish the anatomy and motor function of the upper gastrointestinal tract. In most cases where gastroparesis can be presumed or established, prokinetic therapy will be tried. A number of agents are available, with variable efficacy and tolerance. Rarely, in case of debilitating refractory symptoms, experimental or invasive therapies can be tried such as injection of botulinum toxin, enteral feeding tube insertion, gastric electrical stimulation or surgery.

American Gastroenterological Association technical review on the diagnosis and treatment of gastroparesis

This literature review and the recommendations herein were prepared for the American Gastroenterological Association Clinical Practice Committee. The paper was approved by the Committee on May 16, 2004, and by the AGA Governing Board on September 23, 2004.

Treatment of gastroparesis

Gastroparesis is a condition of impaired gastric motility that can be chronic and result in decreased quality of life and complete disability. Once the diagnosis of gastroparesis is established, the clinician's attention should immediately focus on restoring nutritional status, providing symptomatic relief from nausea and vomiting, and improving gastric motility. Combination therapy is the rule rather than the exception, and most patients require multiple prokinetic and antiemetic modalities for adequate symptom relief. Currently available medications are often inadequate to achieve therapeutic goals, and newer modalities, such as gastric electrical stimulation, which has been shown to decrease symptoms and improve quality of life, should be employed at a low threshold. Several novel therapeutic options are under investigation and may also become part of the routine treatment of gastroparesis.